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Taya2010 [7]
3 years ago
13

Say a hacker has a list of n distinct password candidates, only one of which will successfully log her into a secure system. a.

If she tries passwords from the list at random, deleting those passwords that do not work, what is the probability that her first successful login will be (exactly) on her k-th try?
Mathematics
1 answer:
alexdok [17]3 years ago
7 0

Answer:

The probability is \frac{1}{n}

Step-by-step explanation:

If she has n distinct password candidates and only one of which will successfully log her into a secure system, the probability that her first first successful login will be on her k-th try is:

If k=1

P = \frac{1}{n}

Because, in her first try she has n possibles options and just one give her a successful login.

If k=2

P=\frac{n-1}{n} *\frac{1}{n-1} =\frac{1}{n}

Because, in her first try she has n possibles options and n-1 that are not correct, then, she has n-1 possibles options and 1 of that give her a successful login.

If k=3

P=\frac{n-1}{n} *\frac{n-2}{n-1} *\frac{1}{n-2} = \frac{1}{n}

Because, in her first try she has n possibles options and n-1 that are not correct, then, she has n-1 possibles options and n-2 that are not correct and after that, she has n-2 possibles options and 1 give her a successful login.

Finally, no matter what is the value of k, the probability that her first successful login will be (exactly) on her k-th try is 1/n

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Mam I can speek

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3 years ago
How do you inverse 3x-4y=6
vladimir1956 [14]

Answer:

To find the inverse you switch x and y

Step-by-step explanation:

3y-4x=6

So 3y = 4x+6

and Y = 4/3x + 2

5 0
3 years ago
Read 2 more answers
A grocery store clerk put only cans of tomato soup and cans of chicken soup on a shelf. The ratio of the number of cans of chick
larisa [96]

Answer:

9 cans of tomato soup

Step-by-step explanation:

We are told that only cans of tomato soup and cans of chicken soup are put on the shelf.

Now, we are told that the ratio of the number of cans of chicken noodle soup to the total number of cans on the shelf was 8 to 17.

In fraction, this is 8/17

Now, this implies that there are 8 cans of chicken noodle soup while there are a total of 17 cans on the shelf.

Thus,

Since only cans of chicken noodles and cans of tomato soup are on the shelf, it means;

Cans of tomato soup = 17 - 8 = 9

8 0
3 years ago
Approximate <img src="https://tex.z-dn.net/?f=-8%20%2B%5Csqrt%7B20%7D" id="TexFormula1" title="-8 +\sqrt{20}" alt="-8 +\sqrt{20}
alisha [4.7K]

The value of the radical expression -8 + √20 when expanded and solved is -3.6, based on the given parameters

<h3>What are equivalent expressions?</h3>

Equivalent expressions are different expressions that have equal values when evaluated and compared

<h3>How to approximate the radical expression?</h3>

The expression is given as:

-8 + √20

The above expression is a radical expression

So, we start by doing the following

Express 20 as 5 * 4

-8 + √20 = -8 + √(5 * 4)

Split the radical expression √(5 * 4)

-8 + √20 = -8 + √5 * √4

Evaluate the square root of 4 i.e. √4 = 2

-8 + √20 = -8 + √5 * 2

This gives

-8 + √20 = -8 + 2√5

Evaluate the square root of 5

-8 + √20 = -8 + 2 * 2.2

Evaluate the product of 2 and 2.2

-8 + √20 = -8 + 4.4

Evaluate the difference

-8 + √20 = -3.6

Based on the given parameters, the value of the radical expression -8 + √20 when expanded and solved is -3.6

So, the complete equation is:

-8 + √20 = -3.6

Read more about equations at:

brainly.com/question/2972832

#SPJ1

5 0
1 year ago
Judy Clark went to Reel Bank. She borrowed $7,800 at a rate of 6 1/2%. The date of the loan was September 2. Judy hoped to repay
abruzzese [7]

Answer:

$7995.85

Step-by-step explanation:

We will use simple interest formula to solve our given problem.

A=P(1+rt), where,

A = Amount after t years,

P = Principal amount,

r = Annual interest rate in decimal form,

t = Time in years.

r=6.5\%=\frac{6.5}{100}=0.065

t=\text{141 days}=\frac{141}{365}\text{ year}

A=\$78001+0.065\times \frac{141}{365})

A=\$7800(1+0.065\times 0.38630136986)

A=\$7800(1+0.025109589041)

A=\$7800(1.025109589041)

A=\$7995.85479

A\approx \$7995.85

Therefore, Judy will will pay back on January 20: <u>$7995.85</u>.

8 0
3 years ago
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